Propulsion power system



Feb. 21, 1967. J, N CE 3,304,906

PROPULSION POWER SYSTEM Filed July 1, 1965 John FA/ace,

United States Patent 3,304,906 PROPULSION POWER SYSTEM John F. Nace, Schenectady, N.Y., assignor to General Electric Company, a corporation of New York Filed July 1, 1965, Ser. No. 468,812 1 Claim. (Cl. 115-34) My invention relates to a system for propelling water vehicles and more particularly to a propulsion system for ships that features interchangeability between a quiet gearless drive and a conventional drive.

In the operation of ships and other water vehicles, it is often desirable to interchange between a ships conventional propulsion system, which has a tendency to generate some noise, and an alternate drive which is almost completely silent. Both drives should be capable of operating the same propeller, and the silent drive should also be capable of operating in conjunction with the conventional high speed drive during normal operation, to add more power thereto; -Ship propulsion drives presently employed require gearing or other high noise level transmission equipment even during the most silent operation available. In one particular propulsion system presently in use, the propeller is driven through conventional gearing for normal high speed operation and, even for silent operation the propeller is still driven through a substanital part of this same noisy gearing system. Thus, the desired silent operation is not in reality achieved. A ship propulsion system is then needed wherein substantially noiseless, gear free, operation is available when desired. My invention envisions a water vehicle propulsion system having two interrelated drives which both operate the same propeller, one drive which is gearless for use during silent operation and another which is employed for conventional high speed operation.

The chief object of my invention is the provision of a water vehicle propulsion system having a silent, gearless, drive.

Another object of my invention is the provision of a ship propulsion system which has a silent drive and a conventional drive which both operate the same propeller.

A further object of my invention is the provision of a ship propulsion system which employs a noiseless drive which may be used alone or in conjunction with the main propulsion system, to drive the ship.

These'and other objects of my invention will be more readily perceived from the description which follows:

In carrying out the objects of my invention, I provide a propulsion system for ships which has alternative turbine drives, a conventional high speed drive and a silent gear-free drive, both of which drive thesame propeller,

' the latter drive being capable of operating alone or in conjunction with the high speed drive to increase the power thereof. Significantly, the silent drive is substantially noiseless, not requiring any gears for its operation.

The attached drawing illustrates a preferred embodiment of my invention in which:

The figure is a view of the ship propulsion system of my invention.

In the figure there is shown a view partially in cross section of the ship propulsion system which embodies my invention. The construction includes gas turbines 2, 3, and 4 which provide the propulsion force to drive the water vehicle, such as a ship. Turbines 3 and 4, which are conventional single shaft, simple cycle combustion gas turbines, comprise compressor 6, combustion system and turbine wheel 12. In operation, air is brought into compressor 6, as shown by arrows 9 from the atmosphere by a suitable air inlet within the ship, such as plenum 8. The air pressure is substantially increased in compressor 6 and then the air is passed through combustion system 10 3,304,906 Patented Feb. 21, 1967 wherein fuel is injected and burned therein in the presence of the compressed air. The working fluid, consisting of hot gases resulting from the burning process now expands through turbine wheel 12 to generate mechanical motion and drive suitable transmission means, such as shaft 31 to provide the ship with the required power for effective propulsion. The hot gases after driving turbine wheel 12 are exhausted to the atmosphere through duct 14, as shown by arrow 15. The turbine described is but.

one of many that can be successfully employed with my propulsion system. Alternatively, two turbine wheels may be employed in place of single turbine wheel 12 to form a simple cycle, two shaft combustion turbine. In this case, the first turbine wheel, which operates at high pressure, exhausts the hot gases emanating therefrom to the second turbine wheel, which operates at low pressure to drive a suitable output, such as shaft 31. This arrangement permits output shaft speed variations independent of compressor speed when desired. Another type of turbine that may be employed is a regenerative cycle turbine, which is illustrated with respect to turbine 2. This turbine is exactly the same as turbines 3 and 4 except that the gas exhausting through duct 61 is employed to heat the compressed air before it enters combustion system 11. The compressed air passes from compressor 16 int-o the area of combustion system 11, wherein it is bled off through passage 66 to be heated in regenerator 62 by the exiting exhaust gas. The heated compressed air then passes back through passage 64 and into combustion system 11 wherein it is mixed with fuel and ignited in the same manner as before. By using regenerator 62, the amount of fuel needed to achieve the proper combustion in chamber 11 is substantially reduced. In a like manner, as aforementioned, one or two turbine wheels are employed, at 13, to finally provide the mechanical output that drives shaft 20. Also, the regenerator as described with respect to turbine 2 may also be successfully employed with either or both of the other turbines, 3 and 4. A steam turbine or diesel engine can also be employed in place of any or all of the turbines aforementioned. It will thus be appreciated that there are many types of prime movers, some of which have been described, which can "be successfully employed with my invention, for effectively imparting power to propeller 32.

The mechanical power produced by turbine 2 enters generator 22, which is preferably a water tight marine type generator, to be converted therein to electrical energy. Suitable electrical transmission means, such as wires 24, transmit the electrical energy to motor 26 which in turn converts the energy back into mechanical energy to impart the spinning motion to shaft 28, and thereby propeller shaft 30 and thrust producing means or propeller 32 to drive the ship. Thus during silent operation when turbine 2 previously described is the sole means of propulsion for the ship, power transmission between turbine 2 and propeller 32 is accomplished without any gearing or other noisy transmission system, save what is inherent in the turbine motor and generator themselves. Therefore, silent, substantially noise-free operation is achieved for propelling the ship or other water vehicle when noise suppression is essential to the successful completion of the ships journey. v Motor 26 may be reversible so that the direction of propeller 32 may be reversed if desired for rearward motion of the ship. It is noted that alternatively shaft 20 and shaft 28 may be combined so that turbine 2 directly drives propeller 32 with no auxiliary equipment therebetween. Also by the use of generator 22 and motor 26, the positioning of turbine 2 with respect to propeller 32 is not critical since the only connection between the two is by means of electrical wires 24. Thus, by the use of motor 26 and generator 22 turbine 2 can be positioned as desired without regard to the position of propeller 32, and also reversibility can be employed, when desired. It is also noted that a battery, a fuel cell, a reactor, a hydraulic system or other suitable energy generation means may be employed in place of turbine 2, to drive motor 26.

Turbines 3 and 4 provide the main propulsion means by respectively driving shafts 31 and 33, which interconnect by means of gear train 34 to propeller shaft 30 and thereby to propeller 32, to drive the ship. The principal gear of gear train 34 is main gear 36 which is positioned perpendicular to and surrounding shaft 28, but spaced therefrom. Extension 38 of gear 36 proximate propeller 32 and extension 30 on the other side thereof provide the requisite support to the gear to insure its correct position and alignment and thereby proper operation thereof. The remainder of gear train 34 will be discussed at a later point. A suitable joining means such as a clutch, as provided to connect gear train 34 through gear 36 to shaft 28, for turbines 3 and 4 to transmit their power through the gear train to shaft 28 and thereby to propeller 32. A preferable means of effectuating this joining is to provide flange 29 on shaft 28, perpendicular thereto and mating flange 40 which projects from extension 38 of gear 36, also perpendicular thereto, and to shaft 28. Clutch 42 is suitably controlled to interconnect flanges 40 and 29 and thereby gear train 34 with shaft 28 to thereby transmit power to propeller 32. Gear train 34 preferably consists of the minimum number of gears to effectively transmit the rotary motion of shafts 31 and 33 to propeller 32 to impart motion thereto and thereby drive the ship. The forces inherent in the transmission of power and other factors such as vibration of the ship are taken into consideration in proper choice of the gear train to insure optimum operation of the system. A preferred embodiment of this gear train, as illustrated in the drawing, comprises gears 46 and 48 which are rigidly connected to shafts 31 and 33 respectively. Intermeshed with gears 46 and 48 are larger gears 50 and 52 which are connected by small stub shafts 54 and 56 to gears 58 and 60 which then intermesh with main gear 36 to transmit power from the turbines to propeller 32.- The gears employed are helical gears but may be spur gears or any other suitable type of gearing that effectively transmits high speed power. It is thus seen that turbines 3 and 4 effectively transmit power to propeller 32 for normal operation of the ship. A particular embodiment of the transmission system for transmitting the power of turbines 3 and 4 to the propeller is illustrated, but it will be appreciated that there are many embodiments of gear trains and other transmission equipment which may be successfully employed for conveying the power of the turbines to propeller 32.

In operation, turbines 3 and 4 are employed together to drive propeller 32, through clutch 42, or alternatively are used in conjunction with turbine 2, which is employed as aforementioned, so that all three turbines impart their power to drive propeller 32 during high speed operation. It is also noted that either turbine 3 or 4 may be disconnected and the other turbine employed to drive propeller 32 alone, if desired. During silent or cruise operation of the ship, turbine 2 alone drives propeller 32 so that the inherently noisy gearing train 34 is completely eliminated, and preferably remains stationary during this mode of operation. It will be appreciated that the numher and arrangement of turbines and also the exact type of turbines illustrated are merely preferred embodiments of many that may be successfully employed for operation of my propulsion system.

It is further noted that other water movement means, such as jet propulsion, may be employed in place of propeller 32 to drive the ship.

It will be appreciated from the foregoing that my invention attains the objectives set forth. Apparatus embodying the invention is sturdy in construction and well adapted for use in conjunction with ship propulsion. Because of the elimination of the noisy, gearing transmission system during silent operation, the propulsion system may be successfully employed where noise is a barrier to successful operation.

A specific embodiment of my invention has been illustrated but the invention is not limited thereto, since many modifications may be made by one skilled in the art and the appended claim is intended to cover all such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

A propulsion system for driving ships comprising a propeller,

a rotatable shaft integral with said propeller having a flange thereon,

a first propulsion drive comprising a plurality of gas operated turbines, a second propulsion drive comprising a gas operated turbine having a compressor combustion area, turbine wheel and regenerator, regenerative means connected to said second propulsion drive to increase the efliciency thereof comprising a passageway for feeding compressed air from the combustion area to the hot regenerator and another passageway for returning the heated air to said combustion area, said regenerator being heated by the hot exhaust gas exiting from said combustion area,

a generator driven by said second propulsion drive,

a motor, which is electrically driven by said generator, which directly drives said rotatable shaft and thereby said propeller to propel the ship in -a substantially silent manner,

a gear, which surrounds said rotatable shaft, having a flange which is adaptable to be connected to said flange on said rotatable shaft,

a gear train, driven by said first propulsion drive, which in turn drives said gear, and

clutch means which is adapted to connect the flange of said gear and the flange of said rotatable shaft so that power from said first propulsion drive may be employed when desired to propel said propeller in conjunction with the power of said-second propulsion drive.

References Cited by the Examiner UNITED STATES PATENTS 1,332,631 3/1920 Morse 1l50.5 3,134,228 5/1964 Wol-ansky et al ll4l6 FOREIGN PATENTS 247,837 5/1963 Australia. 410,031 6/1934 Great Britain.

MILTON BUCHLER, Primary Examiner. ANDREW H. FARRELL, Examinerv 

